西北旱区参考作物蒸散量空间格局演变特征分析

摘要

Based on meteorological data from 2000 to 2009, including daily temperature, relative humidity, sunshine hours and wind speed of 124 meteorological stations in arid region of northwest China,crop reference evapotranspiration (ET0) were calculated by using of the Penman-Monteith formula, which was nominated by FAO in 1998 and Kriging method. Furthermore, spatial transfer of the centroids of daily mean evapotranspiration zone ( ≥0. 4mm) in crop growing season .from April to September, was analyzed by function of spatial analysis pf GIS. The results showed that the centroids of daily mean evapotranspiration zone ( ≥0. 4mm) described fluctuating two times from east to west and located in the middle region finally. The migration paths of centroids showed from dispersed to concentrated, and then dispersed. The plane distance between starting and end centroid was longest in April, followed by July, September, June and August,and shortest in May. The destination for centroid of every month during crop growing season was different, but most located in Inner Mongolia. Furthermore,the sunshine duration was followed,and the stations where an evapotranspiration change was sensitive to relative humidity account for the minority. The results could provide important information for the research on developing active adaptation measures to ensure food security under climate change. The results were widely acknowledged in agricultural drought monitoring,water resources management and assessment.%利用西北旱区124个站点10a逐日气温、相对湿度、日照时数和风速资料,采用FAO的Penman - Monteith 和Kriging方法对参考作物蒸散量进行估算和空间化,分析2000-2009年作物生长季(4-9月)参考作物蒸散量年际变化≥0.4mm区域质心的空间迁移规律.结果表明,作物生长季(4-9月)年际日均蒸散量变化≥0.4mm地区的质心整体经历从西到东两次波动,最后定位在中东部,质心迁移路径空间变化表现为由较发散变为较集中,然后到较发散；从各月年际变化上看,4月质心迁移平面距离最长,其次为7、9、6、8月,5月最短；迁移方向没有明显变化规律,各月质心最后到达位置各不相同,但是都处于内蒙古地区.近10a(2000 - 2009年)来,4-9月参考作物年际日均蒸散量变化≥0.4mm区域的面积呈现一定的增加趋势,其中4、6、9月的波动较大,年际变化趋势不明显,而5、7、8月面积变化曲线呈稳定增加趋势(P＜0.05).8月蒸散量对平均温度正向敏感的站点最多,敏感性较高的站点主要分布在中部和南部地区,其次是日照时数,蒸散量对相对湿度敏感的站点最少.研究结果对农业旱情监测、水资源管理和评价具有重要意义.